@article{oai:niigata-u.repo.nii.ac.jp:00006374,
 author = {Yamano, Miki and Watanabe, Hidenobu and Matsubayashi, Hiroyuki and Iga, Yoshiroh and Murayama, Kazuo and Matsuda, Keiji and Nishikura, Ken and Ajioka, Yoichi and Shirai, Yoshio},
 issue = {3},
 journal = {Acta medica et biologica, Acta medica et biologica},
 month = {Sep},
 note = {We report an interesting case with a primary ulcerating tumor of the ampulla of Vater associated with multiple primary pancreatic ductal microadenocarcinomas. All of these pancreatic microcarcinomas (number, 69; size, 0.04-1.25mm) were histologically proved to be primary and independent of each other, and were distributed throughout the head, body, and tail of the pancreas. They were all located in the small interlobular ducts and the ductules (including intercalated ducts and centroacinar cells). Sixty-three of 69 microcarcinomas were in-situ carcinomas, and the remaining 6 were microinvasive. All microcarcinomas were well-differentiated tubular adenocarcinomas with ordinary cell phenotypes, high-grade cytologic atypia, and adjacent only to normal ordinary pancreatic ductal cells, but not to mucous cell hyperplasia. Immunohistochemically, all of the microcarcinomas showed p53-protein overexpression (p53 positive index: 91.6 ± 8.10% in 12 tumors tested), high proliferative activity (Ki-67 positive index: 64.9 ± 13.3% in the same 12 tumors), and no Ki-ras mutation detected by nested PCR-RFLP in the 12 carcinomas. We concluded that pancreatic microcarcinoma in this case arose from ordinary pancreatic ductal cells of the small ducts and ductules by way of p53 alteration without Ki-ras mutation, and that histogenesis was different from that of the more common Ki-ras-mutated carcinoma arising from metaplastic mucous cells of mucous cell hyperplasia.},
 pages = {113--120},
 title = {Primary Pancreatic Ductal Microcarcinomas Arising from Interlobular Duct and Ductules},
 volume = {46},
 year = {1998}
}